October 1, 2008
NOAA Addresses the Marine Debris Problem
By Bamford, Holly A McElwee, Kris; Morishige, Carey
Creating Partnerships and Innovative Solutions to an Ocean and Coastal Threat In 2005, the receding iloodwaters of Hurricane Katrina deposited tons of material offshore, creating a marine debris problem hazardous to fishing and boating activities. Thousands of mi les away i n the Northwestern Hawaiian Islands, more than 50 tons of derelict fishing gear accumulates in the shallow waters of these remote islands each year, damaging coral reefs and entangling endangered Hawaiian monk seals. North of the Hawaiian Islands in the open Pacific Ocean, vast amounts of small plastic debris concentrate in certain areas and may be eaten by sea turtles, seabirds or other marine life, with potentially life-threatening effects. Closer to shore in areas such as the Chesapeake Bay and the California coast, derelict fishing gear continues to "ghost fish," a term for when lost or abandoned fishing gear continues to catch prey without being retrieved by fishermen to harvest.
In all parts of the world, marine debris continues to present a hazard to marine ecosystems and safe navigation. The problem of marine debris requires a continued effort to establish sustainable programs, partnerships and innovative technologies to remove, reduce and prevent this form of marine pollution from impacting the ocean environment.
To improve efforts to address marine debris, in 2005 the U.S. Congress created the Marine Debris Program (MDP) within the National Oceanic and Atmospheric Administration (NOAA). The NOAA program was formalized in 2006, when President George W. Bush signed the Marine Debris Research, Prevention and Reduction Act into law. This act established a centralized program within NOAA to organize, strengthen and enhance marine debris efforts within the agency, with its partners and the public.
NOAA's Marine Debris Program
The NOAA MDP is a national program that supports both nationwide and international efforts focused on identifying, preventing and reducing the occurrence of marine debris. These efforts protect the United States' natural resources, oceans and coastal waterways from the impacts of marine debris. The type of marine debris the program addresses is persistent, solid material that is disposed of or abandoned in the marine environment.
The MDP operates out of the NOAA headquarters in Silver Spring, but has a handful of program coordinators located around the coastal United States who support regional projects. While program coordinators lead a number of projects, a majority of their time is spent coordinating with other NOAA programs and nonfederal partners who implement projects funded by the MDP. These projects are awarded to the partners through three competitive proposal processes developed by the MDP. This partnership approach allows for the broadest reach of marine debris reduction and prevention activities tailored to regional debris problems.
Due to the diversity of the ocean and coastal environments, marine debris projects vary widely from region to region and require innovative solutions to address each unique challenge. Since 2005, the MDP has funded more than 100 projects across the nation in partnership with others to address identified needs in marine debris research, prevention and monitoring. Many projects require recasting or creating technologies and methods to successfully carry out the goals of the work. For example, proven technologies such as side scan sonar and manned submersibles have been implemented in various marine debris projects. Several of these projects and their methods are discussed below.
Selected U.S. Projects
Ghost Fishing in Chesapeake Bay. The Chesapeake Bay is home to one of the nation's largest blue crab fisheries. In the bay, crab traps are the primary harvesting method used. Estimates suggest that, historically, as many as 500,000 crab traps (pots) were set within the bay on a typical day during the fishery's peak season. The NOAA Chesapeake Bay Office (NCBO) has conducted routine benthic habitat surveys and discovered a large number of derelict crab traps lying within blue crab habitat. To investigate this finding, NCBO implemented the derelict fishing gear identification, mapping and assessment project to quantify "ghost traps" in various areas of the bay. To do this, NCBO and its research partners use side scan sonar to locate, identify and count derelict traps. Scientists then check how well the side scan sonar detects derelict traps by ground- truthing the findings using underwater video cameras, grappling devices and divers. Project researchers have also conducted experiments to estimate the effects of these ghost fishing derelict traps on the populations of blue crab and other bycatch species.
Survey results from this study, which began three years ago, show ghost trap densities in surveyed areas range from 10 to 690 traps per square kilometer. The overall number of lost crab traps in the Maryland portion of the Chesapeake Bay is approximately 40,000. Further research and analysis will refine these numbers and the NCBO's understanding of how derelict crab traps affect living resources in the Chesapeake Bay.
Hawaii Shoreline Aerial Surveys. Derelict fishing gear in Hawaii's coastal and marine habitats presents a potentially lethal entanglement hazard to numerous marine species, most notably the critically endangered Hawaiian monk seal, the threatened green sea turtle and the endangered humpback whale. In addition to fouling coastal habitats and presenting an immediate threat to wildlife, derelict gear also damages coral reefs. This project, led by the NOAA Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division, began in 2006. Aerial helicopter surveys were conducted off the coastlines surrounding the Hawaiian islands of Kauai, Hawaii, Lanai, Maui, Molokai and Oahu to determine the distribution and abundance of marine debris on the beaches and in nearshore waters.
More than 700 derelict fishing gear locations were mapped in a geographic information system, which was subsequently used to support crews in removing more than 37 tons of derelict fishing gear from the beaches around Lanai and Oahu. Results from these surveys are being used to assist coastal managers, along with local communities, in identifying and prioritizing cleanup areas and targeting specific sites for future monitoring. This year, a follow- up aerial survey is being conducted to assess accumulation rates and provide updated maps of debris.
Hurricane Debris Surveys. During the 2005 hurricane season, hurricanes Katrina and Rita inflicted severe damage on the Gulf of Mexico coastal region and deposited huge amounts of debris in the water off the Gulf Coast. To identify and map this debris, survey work began in September 2006 in Alabama, Mississippi and eastern Louisiana. NOAA's Office of Coast Survey used side scan sonar to survey the area and found more than 5,000 submerged potential debris items, referred to as contacts. The sonar contacts were mapped and posted, along with additional contact data, on the project's interactive Web site to advise boaters and assist with ongoing marine debris removal work.
In 2008, these efforts have continued with offshore surveys along the Louisiana coast to map new sonar contacts and make the information available on the project Web site. The Web site provides printable static maps in PDF format, along with geographic coordinates that can be easily downloaded into a global positioning system and an interactive mapping option that allows the user to zoom into a specific area to get more information, including the location and estimated contact dimensions. The Web site has become a valuable resource not only to the public, but also in the coordination and planning of survey and removal operations.
Debris Detection at Sea. Fishing gear that has been lost or discarded is a chronic threat to the coral reef ecosystems of the Papahanaumokuakea Marine National Monument in the Northwestern Hawaiian Islands. Derelict gear entrained in the North Racific Subtropical Convergence Zone is strained out by the reefs and shoals of the monument, causing physical damage to the reef and endangering wildlife. Derelict fishing gear has been the target of intensive removal efforts since 1996, but additional efforts are needed to keep pace with deposition rates, as well as to remove the debris before it has a chance to impact the monument.
The ability to predict areas of high marine debris concentration in the open ocean is currently limited. A summit of NOAA, other government agencies and private sector experts in marine debris, oceanography, remote sensing and unmanned aircraft systems (UASs) will be held later this year to review current knowledge, share information and develop strategies that will move NOAA and its partners closer to an operational mode of at-sea detection and removal of marine debris. In addition, nearshore flights of a UAS will test airworthiness, autonomous flight capabilities, video acquisition and anomaly detection.
These tests will allow better evaluation of UASs and other technologies for locating marine debris at sea, with the goal of removing it before it harms natural resources or imperils navigation and fishing efforts. California Deepwater Debris. Historically, efforts to address marine debris have focused mainly on the cleanup of shallow shoreline and subtidal (less than 30 meters deep) areas. Because of this, little is known about the extent of the problem and its potential impact on seafloor habitats in deeper waters. Since 1993, researchers with NOAA Fisheries and other organizations have collected information on fishes, invertebrates, seafloor habitats and marine debris in deep waters (20 to 365 meters) off central and southern California.
These researchers use the manned submersible Delta to make direct observations, which are also recorded by video cameras. These researchers are interested in the distribution, abundance, type and possible impact of the marine debris.
Results have shown that the primary source of debris is fishing, both recreational and commercial, though many other types of debris have also been observed.
To date, most of the gear recorded was not actively fishing, and few entangled animals were observed. Some of the debris is used as habitat by marine organisms.
The 2008 study builds on previous work and looks at the changes in marine debris that have occurred over the past 10 to 15 years. Marine debris locations will be mapped and debris "hot spots" will be identified.
It is clear that the problem of marine debris is broad in scope and nature. In order to effectively address the issue, a continued coordinated effort is needed that includes long-term partnerships that support marine debris technology unique to each region. Since 2005, the NOAA MDP has initiated more than TOO projects around the country to address this problem. Depending on the nature of the marine debris issue, various standard techniques and methods have been deployed in innovative ways to more directly detect, monitor, remove and assess marine debris in U.S. oceans and seas. These techniques range from aerial surveys thousands of feet above the water to submersibles near the ocean floor. Through the ongoing efforts of the NOAA MDP and its partners, the protection and conservation of the nation's natural resources, oceans and coastal waterways will continue.
The authors would like to acknowledge the project's partners, NCBO, NOAA Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division, Gulf of Mexico Marine Debris Project, Papahanaumokuakea Marine National Monument and NOAA Southwest Fisheries Science Center.
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First ocean test flight of the unmanned aerial vehicle Malolo I off the north shore of the island of Oahu, Hawaii.
(Above) Information on submerged debris located with side scan sonar (top right) and debris removal efforts (bottom right) in the Gulf of Mexico is available on the project Web site (left). (Photo courtesy of NOAA and the Louisiana Department of Wildlife and fisheries.)
(Below) Side scan sonar (top left) shows locations of derelict crab traps in the Chesapeake Bay (right). Tagged crabs help determine the impact of lost gear (bottom left). (Photo courtesy of / VOAA.)
By Dr. Holly A. Bamford
Pacific Islands Coordinator
National Oceanic and Atmospheric Administration Marine Debris Program
Silver Spring, Maryland
Dr. Holly A. Bamford is the program director for the National Oceanic and Atmospheric Administration Marine Debris Program. Bamford has studied in the field of coastal and ocean pollution for more than 15 years.
Kris McElwee is the Pacific Islands coordinator for the National Oceanic and Atmospheric Administration (NOAA) Marine Debris Program and the NOAA Coral Reef Conservation Pro-gram, on contract from I.M. Systems Croup.
Carey Morishige is the outreach coordinator with the National Oceanic and Atmospheric Administration Marine Debris Program, on contract from I.M. Systems Croup. Carey holds an M.S. in animal science and a B.A. in zoology from the University of Hawaii and has worked in Hawaii's marine conservation field for more than seven years.
Copyright Compass Publications, Inc. Sep 2008
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